fairchild



the said spindle, the tendency of which is to force the spring J. M. FAIRCHILD, O F- NEW HAVEN, CONNECTICUT, ASSIGNOR TO HIM- SELF, J. K. BUNDY, AND J. M. TOWNSEND, OF SAME PLACE.

Leners Parent No. 71,863, am@ December 1o, 1867.

@he ttehnlt nftrnh tu in time etttrs what mit mating tnt nt tige train.

IO ALL WHOM IT MAY CONCERN:

-Be it known that I, J. M. FAIRCHILD, of New Haven', in the county of New Haven, and State of Connecticut, have invented a new Improvement in Self-AdjuStingvMa-gnet; and I do hereby declare the following, when taken in connection with the accompanying drawings, anid the letters of reference marked thereon, to be a full, clear, and exact description of the same, and `,which said drawings constitute part of this specification, und represent, in-

Figure 1, a top view, and in Figure 2 a longitudinal central section of one of the magnets.

This invention relates more particularly to improvement in the magnets such as are used in Morscs telegraphing instruments. It is well known to those experienced in the use of such magnets,

that upon any variation of strength of the current it is necess ary to adjust the magnet in order to the proper working of the instrument, that is, to place the magnet farther from the armature according as the current is stronger. T olavoid this adjustment, and at the same time to cause the machine to be always in condition to operate, is the object of l my invention, and consists in the arrangement of a spindle within thel core of the magnet, so that the said i spindle will by the action of the magnet upon the soft-iron head of' the spindle tend to draw the said spindle into or the head of the spindle nearer to the magnet and farther from the armature in proportion as the strength of the current on the line may be increased, or relieve the head so as to approach the armature in proportion as the currentis diminished.

In order .to the clear understanding of my invention, the accompanying drawings.

A A represent two ordinary magnets to be placed in the usual relation to the armature. Centrally in the core of each of the magnets I arrange a spindle, a, supported in a bearing I will proceed to describe the same as illustrated in Zz, and upon a spring acting upon from the magnet. Outside the magnet, and upon The spring upon the spindle should only. be suffi' but when the magnet is in circuit, in proportion as the current is stronger, s0 will the head :C be drawn toward the magnet and away from the armature, and consequently, as the currentdiminishes,the head C will bc forced from the magnet nearer` to the armature, thus causing the magnets to be always in the :mostperect adjustmentrelative to the armature. Thus, by this simple the spindle, I tix a soft-iron head, C, or other suitable metal. cient to throw the magnet out when the magnet is not charged,

vmeans I am enabled to overcome one of the principal difficulties in telegraphing, that is, the adjustment of the magnet, which now requires a skillful operator.

Having thus fully described my invention, what I claim as new an Patent, is- A The arrangement of the head C combined with the magnet, so as to be selfarmature, substantially as herein set forth.

d usefuhand desire to secure by Letters adjusting in relation to the i J. M. FAIRCHILD.

Wltnesses J oHN E. EARLE, GEORGE JoNEs. 

